Garrison was claimed by the Golden Knights in the 2017 expansion draft. After playing four games for them early in the season, he was placed on waivers in late October. He was back up with Vegas for four more games in late January and early February. He finished the 2017/18 NHL season with one assist in eight games.

He spent most of the campaign with the AHL’s Chicago Wolves, racking up eight goals and 20 assists in 58 games.